Krillin is revived after being killed by Frieza thanks to the use of the Namekian Dragon Balls.
After Frieza brutally kills Krillin on Planet Namek, Goku's rage unleashes his Super Saiyan transformation. While Goku battles Frieza, the remaining Z Fighters and Namekians work to gather the Namekian Dragon Balls. These Dragon Balls, unlike Earth's, can grant multiple wishes and revive people an unlimited number of times.
The first wish made is to teleport Piccolo from Earth to Namek. This is done because Dende explains that if Piccolo dies, then Kami also dies, and if Kami dies, the Earth Dragon Balls will be useless. The second wish teleports all but Goku and Frieza (who refuse to leave) to Earth.
Once Frieza is defeated by Goku, the Z Fighters return to Namek to make the final wish: to revive all those killed by Frieza and his men. This wish brings Krillin back to life, along with all the Namekians killed by Frieza's forces.
Following his resurrection, Krillin dedicates himself to training for the upcoming threat posed by Doctor Gero and his androids, reflecting his commitment to protecting Earth. He trains for three years preparing to face the androids.
